I thought that for once I had no comment about the subject at hand, but then realized that I could suggest using "glacial acetic acid," probably still available from photo supply stores, in place concentrating vinegar by phase separation.

Of course, this wouldn't concentrate the cider flavour, which might be a drawback. Or, though it looks like work to me, you might just enjoy jacking.

Bear with me: I'm having a Jon Singer Moment.

I've got no actual experience with jacking, so I may be way off base here.

But it seems to me that if the vineagar melts faster than the water does, it's because it has a lower freezing point than water does. And it might be that if you allowed the ice to melt in your refrigerator, the difference in melting rate between the water and the vineagar would be enhanced, and the resulting vineagar melt would be stronger. The process would take rather longer, but with better results.

(See, a degree in physics can be put to good use!)

That thought has occurred to me, too; but along with all its other charms, my POS refrigerator barely has room for my normal groceries.

Thinking about Alan's comments and adding the information from a sophomore year course on solidifiation phenomena, I would venture to suggest that cooling the vinegar to refrigerator temperatures, or even melting-ice temperatures, before sticking it in the freezer might also improve results.

This is because the interface between solid and liquid is smoother and traps less liquid during freezing when the temperature gradient across the solidification interface is lower.

You could also look at the cider vinegar-water phase diagram and find an optimal temperature at which mostly-water ice would freeze out of mostly-acetic-acid vinegar. Then if you stirred the solution as it froze, you could judge by thermometer the optimum time to remove the slurry and filter out the ice.

But your freezer probably doesn't have room for an electric mixer.

Or you could invent some nanomachines that sort acetic acid from water (preserving cider-flavor components), program them with the optimal concentration, and let 'em rip.

But you probably don't have room for the nano-machine generators in your refrigerator, either.

Yeesh. Let the poor woman jack some vinegar, hey guys?

X, I'd rather program the nanomachines to separate water from everything else, which is a far more practical approach than trying to identify what is or is not an important component of cider vinegar.

Owner of a large refrigerator,
Bob

I don't strain partly-frozen slurry. I let the whole thing freeze solid, then let the vinegar melt out of it. This works. I discovered it inadvertently one day when I'd left a block of frozen fruit juice to melt. The runoff was stronger than I remembered the original juice being, and the ice left behind was almost flavorless.

I always thought that this was rather the point of Slush Puppies. The best ones are the raspberry ones, because they're electric blue. So Marianne sucks up all the blue colouring, artificial flavours, sugar and whatnot, dyeing her fingers and tongue blue in the process. She leaves a collection of sludgy flavourless, colourless ice underneath. Which she discards. But presumably it starts as a consistent liquid.

Teresa,
I gathered that you didn't strain the slurry now, but an approach very like this is used for industrial separation processes. I assure you that if you were making more than about 50 bbl of concentrated vinegar in your partment, you would want to look into this.

I didn't seriously expect you to explore the vinegar-water phase diagram, install a mixer in your freezer, connect a thermocouple and wait for an alarm at a set point, etc.. I might more seriously recommend that you look into using a water-faucet aspirator to pull a vacuum on a pressure cooker you were using for vacuum-enhaced distillation.

Water-faucet aspirator? Say on. Does Mr. Bernoulli come into this?

Very perceptive of you, Teresa, though I think the credit is given more to Signor Venturi than Bernoulli.

Flowing water enters a channel in the body of the aspirator. This channel decreases in diameter at a point along its length. As the water passes into the narrowed section of the channel its linear velocity increases and its pressure decreases. The narrow part of the channel, where the pressure is low, is provided with an intersecting channel which opens to the outside of the aspirator device's body. In operation, this channel is connected by a pipe or hose to the vessel in which one wishes to reduce the pressure.

Air from that vessel flows along the pipe or hose into the aspirator, where the pressure is lower than in the vessel. They can't really pull a hard vacuum, and there's a tendency for water to be drawn back up the connecting channel as pressure at the throat of the aspirator channel varies.

Water faucet aspirators are often found in chemistry labs. A typical application would be to connect the aspirator to the side-arm of a side-arm Erlenmeyer flask and insert a filter funnel through a stopper into the flask's mouth. The pressure differential between the atmosphere and the inside of the flask increases the flow of liquid through the small holes in the filter funnel.

I found a lab equipment vendor listing of such a device for $111, but I'm sure they could be made or bought for less. The device's performance is interesting, though, "The water aspirator will evacuate 10a0liters of air to less than 60a0mma0Hg in less than 6a0minutes at 15a0psi water pressure. " That's over a two gallon volume reduced to about a thirteenth of an atmosphere.

I found an ASU page which showed a home experiment in vacuum, seemed to assume a cheap plastic aspirator, so if you have any science lab supply stores in town, you might be able to get something for a few dollars. Mortuary supply stores also carry aspirators, though I expect they'd be overpriced.

If you're interested in rolling your own, you might find instructions for constructing a simple aspirator in a book on constructing simple science experiments. UNESCO used to have some good books like this, but I would guess that there are a couple someplace at the Strand Bookstore.

Oh, if you do this, use a "vacuum breaker" to keep the contents of the vacuum vessel from being sucked back up into the water supply pipes.

A simple mechanism for pulling moderate vacuums using an electric pump can also be constructed. This is useful if you want to avoid using a lot of water to pull a vacuum, but you still need to buy or build the Venturi aspirator device.

Here's a faucet-based pump like what Mr. Webber is describing. I suspect since it's at a pet supply place, it's intended for use in emptying aquaria. No idea if this would give sufficient vacuum for vacuum cooker purposes.

The pump Jeff Youngstrom has linked to works on the Venturi principle and does reduce pressure in the fixture and hose attached to the side of the pump body.

I think the "suction" side of the pump is probably too large to work well pumping air instead of water, though.

Good grief, TB, reduce it on a low heat . Most chefs do it regularly. It won't change the taste all that much. Or try the Pride of Deer Creek marinade found in the green cookbook.

Hi, Mrs Nielsen. I doubt that you remember me, but we met briefly in your home about twenty-five years ago while I was visiting Arizona for LepreCon at the Grand Canyon. Teresa took me on a fun expedition to a high school debate contest in Chandler, and I remember your house on Yucca Circle seeming very strange to a boy raised in Toronto.

Anyway, if we can't have vacuum distillation in every kitchen, it's just not worth the trouble of living here in the future. It would be like not being able to degauss fresh corn, and instead having to eat it off the cob like animals.

Oh, and I wanted to say that I hope you are at least as proud to have Teresa as your daughter as I have been to have her as my friend through those years. She is truly an exceptional person, even if she sometimes does things the hard way.

Thank you.